Do not set branch weight if the branch weight annotation is present.

Summary: ThinLTO will annotate the CFG twice. If the branch weight is set by the first annotation, we should not set the branch weight again in the second annotation because the first annotation is more accurate as there is less optimization that could affect debug info accuracy.

Reviewers: tejohnson, davidxl

Reviewed By: tejohnson

Subscribers: mehdi_amini, aprantl, llvm-commits

Differential Revision: https://reviews.llvm.org/D31228

llvm-svn: 298602
diff --git a/llvm/test/Transforms/SampleProfile/branch.ll b/llvm/test/Transforms/SampleProfile/branch.ll
index 2ef01a7..5a5160e 100644
--- a/llvm/test/Transforms/SampleProfile/branch.ll
+++ b/llvm/test/Transforms/SampleProfile/branch.ll
@@ -87,7 +87,9 @@
   %6 = load i32, i32* %u, align 4, !dbg !46
   %7 = load i32, i32* %limit, align 4, !dbg !48
   %cmp5 = icmp slt i32 %6, %7, !dbg !49
-  br i1 %cmp5, label %for.body, label %for.end, !dbg !50
+  br i1 %cmp5, label %for.body, label %for.end, !dbg !50, !prof !80
+; CHECK: edge for.cond -> for.body probability is 0x73333333 / 0x80000000 = 90.00%
+; CHECK: edge for.cond -> for.end probability is 0x0ccccccd / 0x80000000 = 10.00%
 
 for.body:                                         ; preds = %for.cond
   call void @llvm.dbg.declare(metadata double* %x, metadata !51, metadata !17), !dbg !53
@@ -237,3 +239,4 @@
 !77 = !DILocation(line: 20, column: 4, scope: !6)
 !78 = !DILocation(line: 21, column: 4, scope: !6)
 !79 = !DILocation(line: 22, column: 2, scope: !6)
+!80 = !{!"branch_weights", i32 90, i32 10}